DISA 0 Ring

If your carfull you can remove the distribution piece without breaking anything. Doru, you just changed your CVV and hose not long ago. You shouldn't have any trouble to clean the distribution unit. The way I clean it, is to remove the part using a very long screw driver to pry up gently at each port front to back. I use throttlbody
cleaner and spray into each port slowly until the whole of the body is full. Walk away afterwards and let the part soak for about 10 min and then come back and use some compressed air to get the junk thats in the part out. Of course have some new 0 rings ready to replace the old parts on the DU.
On checking the DU for vac leaks, you would be surprised how many told me I would hydrolock my engine
by having a few drops of water introduced to the combustion chamber from my methods mentioned.

Thank you guys. I need to change the injector O-rings/clean the injectors as well, so I might clean the distribution piece as well. I noticed some heavy mayo on my dipstick (argh!) so there is some gunk in there for sure. I know I did the CCV about 2 years ago, but after seeing all that mayo last week on my dipstick, I just wonder......

P.S. : if judging by approach: leave some brake cleaner in the distribution piece for a while to dissolve the gunk inside would work also for the CCV? Or will the brake cleaner damage the diaphragm?

Originally Posted by champaign777

yaaa bad guy

here we are :

Metric
inside diameter x thickness = outside diameter (in millimeters)

dealer o-ring : 50MM x 3.5MM ( GREEN COLOR ) = 57MM outside ( updated for bluebee -> M52TU #11617504543 )
chemgigi o-ring : 51MM x 2.5MM ( RED COLOR ) = 56MM outside ( updated for bluebee -> M54 #DO NOT EXIST)

Final decision will be done directly on DIZA ( this weekend )

finally i replaced my DIZA o-ring

The green one ( dealer o-ring from < 2001 ) do not match , no way, its too big for M54 DIZA
The E-BAY chemgigi o-ring match perfect

and to remove the old o-ring was a PITA job

out of these #140 o-rings, which would be more suitable for DISA?

http://www.amazon.com/gp/product/B000FN0ZHA
http://www.amazon.com/gp/product/B000FMUQQQ
http://www.amazon.com/gp/product/B000FMUVSO

In this thread today:
- E39 (1997 - 2003) > Engine code po171

Paul kindly showed how he fixed his M54 rough idle with Permatex around the DISA valve o-ring.
- **Rough Idle**p0174 and p0171**Vacuum Leak**ALL FIXED

It's likely he was unaware of the DISA o-ring source at the time of his rough-idle P074 P071 DIY ... so I ask this question (of him) and of the tribe in general.

QUESTION: Knowing that the source exists for the M54 DISA o-ring, if you had a leak, would you 'still' use Permatex or would you simply replace the o-ring unlubricated?

Originally Posted by champaign777

finally i replaced my DIZA o-ring

The green one ( dealer o-ring from < 2001 ) do not match , no way, its too big for M54 DIZA
The E-BAY chemgigi o-ring match perfect

and to remove the old o-ring was a PITA job

So, the RED O-ring IS the O-ring to get for 2001 face-lift E39's...

http://cgi.ebay.com/ebaymotors/BMW-E...Q5fAccessories

I'm confused.

The original M54 DISA O-ring apparently has a rectangular cross section.

But, if I understand the fix here, you guys are replacing the rectangular o-ring with a circular cross section o-ring. Is that right?

And, what about the 'vertical sealing strips' (which are shown in the photo I previously posted from this thread)?
- Engine code po171

Are people fixing the vertical strips also?

Originally Posted by pshovest

No one had proposed an oring solution when I had the problem and I'm not convinced the oring fix is the best. The M52TU uses an oring, but the M54 DISA seal is not an oring. It is a molded part that doesn't have a round cross section. If the replacement oring is too thick, the DISA won't be properly seated and sealed in the intake manifold. Notice the two vertical sealing strips on the DISA in the photo? The Form-a-gasket fix is less likely to interfere with these seals.

It's been 15k miles and all is well.

bought "#136 Silicone O-RING, Pack of 25" at amazon for $7.
buying lesser quantity had no economical benefit.

fit was "fine"

if I had to buy it again, I'd go with #137 or #138 for perfect snuggier fit.

Originally Posted by Jason5driver

So, the RED O-ring IS the O-ring to get for 2001 face-lift E39's...

http://cgi.ebay.com/ebaymotors/BMW-E...Q5fAccessories

i really don't care 7$ or 12$
yap, red one from ebay is the way to go , match perfect

silicon is a big NO NO, you don't want to see this staff in your cylinders, don't you ?

Originally Posted by champaign777

silicon is a big NO NO

Makes sense. There is no filter between the DISA and the pistons.

Nobody answered the question about the cross section of the replacement o-rings.

I guess that it's just fine to replace a rectangular cross-section o-ring with a circular cross-section o-ring. Right?

Is this guy who is selling Oring on ebay trust worthy? I've ordered the oring on 14th may and mailed him 2 times but no response or oring yet. I even didn't get any confirmation or mail from him for delivery too. What you guys think of him?

Originally Posted by bluebee

makes sense. There is no filter between the disa and the pistons.

Nobody answered the question about the cross section of the replacement o-rings.

I guess that it's just fine to replace a rectangular cross-section o-ring with a circular cross-section o-ring. Right?

+1

Originally Posted by Nittenyadhav

Is this guy who is selling Oring on ebay trust worthy? I've ordered the oring on 14th may and mailed him 2 times but no response or oring yet. I even didn't get any confirmation or mail from him for delivery too. What you guys think of him?

this guy needs some "kick off" but finally you will get it

Originally Posted by champaign777

i really don't care 7$ or 12$
yap, red one from ebay is the way to go , match perfect

silicon is a big NO NO, you don't want to see this staff in your cylinders, don't you ?

do you know material from which your replacement O-RING is made?
and whats wrong with silicone? how should it get into cylinders?

Silicone is acceptable for temperature applications between -65 degrees F (-54 degrees C) to 450 degrees F (232 degrees C). It has good resistance to ozone, weather, detergent, salt water, engine and transmission oil, non-petroleum brake fluid, hydraulic fluids that resist fire, vegetable and animal oils, and high molecular weight chlorinated aromatic hydrocarbons.


Silicone is vulnerable to mechanical wear and tear, water and steam over 250 degrees F (121 degrees C), aromatic hydrocarbons (benzene), chlorinated hydrocarbons (trichloroethylene), acids and bases, and hydrocarbon fuels.

Originally Posted by champaign777

this guy needs some "kick off" but finally you will get it

But how do I contact him? I sent 2 mails from ebay but no response. Is there any phone number where I can call him?

Vacuum from the engine would pull the silicone into the cylinders. Now if your smart and use sensor safe silicone there wouldn't be any problem. The only problem with small bits of silicone getting into the cylinders would be that once burned the stuff would contaminate your 02 sensors. The stuff is so sofet that there wouldn't a problem to the combustion chamber, unless your pour huge amounts in. For the amount thats going to be used to seal off the DISA valve, only small and I mean very small particles would be pulled into the engine. I don't see where this would cause any problems what so ever.

Originally Posted by poolman

Vacuum from the engine would pull the silicone into the cylinders. Now if your smart and use sensor safe silicone there wouldn't be any problem. The only problem with small bits of silicone getting into the cylinders would be that once burned the stuff would contaminate your 02 sensors. The stuff is so sofet that there wouldn't a problem to the combustion chamber, unless your pour huge amounts in. For the amount thats going to be used to seal off the DISA valve, only small and I mean very small particles would be pulled into the engine. I don't see where this would cause any problems what so ever.

can't believe you are talking serious about it.
I'm talking abut silicone o-ring, not silicone sealant!!!

Originally Posted by Nittenyadhav

But how do I contact him? I sent 2 mails from ebay but no response. Is there any phone number where I can call him?

tell him negative feedback is on the way , this will help

and for people who want to use silicon as poolman said should be no issue
damage, no damage , finally its your car and your decision and if it worth 10$ then go for it

Hi champain777

Thanks for your reply. I just mailed him again so hope he will get back to me soon. Thanks again.

Originally Posted by poolman

if your smart and use sensor safe silicone there wouldn't be any problem

Ooops. Because I'm debugging lean-mixture pcodes, today, at about 105K miles (2002 BMW 525i), I removed my DISA unit today for a quick look.

1. SES: P1083,BMW 202, Fuel Control Limit Mixture Too Lean (Bank 1 Sensor 1)
2. SES: P1085,BMW 203, Fuel Control Limit Mixture Too Lean (Bank 2 Sensor 1)
3. SES: P0174,BMW 228, System Too Lean (Bank 2)
4. PENDING: P0171,BMW 227, System Too Lean (Bank 1)

The DISA 'looked' OK. But now I had the problem of the o-ring seal.

Looking on my shelf, I found (and used) this stuff as the sealant.

Did I use the right or wrong stuff as a sealant?

go get the o-ring


if you use the sealant that is not sensor safe, you will end up like this.

The picture shown here is a silicone contaminated oxygen sensor. A contaminated O2 sensor will give you lean fuel-air mixture and the car feels very sluggish. You might not get a code but you will get a bad gas mileage.

Originally Posted by chemgigi

if you use the sealant that is not sensor safe, you will end up like this

It makes sense to buy the relatively cheap o-ring if you plan on removing the DISA, so as not to risk the expensive sensors.

The good news, for now, is this response from over here:
- E39 (1997 - 2003) > Car was throwing codes....DISA valve!

Originally Posted by uncmozo

According to the Permatex Ultra Copper Technical Data Sheet, Ultra Copper IS sensor safe. You're fine.

Permatex Ultra Copper Maximum Temperature RTV Silicone Gasket Maker

• Permatex Ultra Copper Technical Data Sheet
• Permatex Ultra Copper MSDS

Originally Posted by pleiades

Is the O-ring on M54 DISA units just an O-ring or more complicated? Has anyone measured that one?

Technically, there is no O-Ring on the M54 DISA units... and that's why there is not one shown on the realoem diagrams. The sealing is done via a built-in "lip" on the base of the unit that mimics an o-ring. Yes, you can gouge out the old sealing to uncover the grove that a normal o-ring can be fitted into, but you have to wonder why BMW made it the way they did, why it's rectangular, and the original seal is moulded and "glued" into place.

Also, and a big assumption here - the reason the DISA units may not have a traditional o-ring fitted, is, what might happen when it wears, or is mis-fitted, and gets sucked down the intake manifold and into the motor?

Putting an o-ring onto an old worn unit might be a bit of a risk perhaps.

Originally Posted by Bazza-Aus

The sealing is done via a built-in "lip" on the base of the unit that mimics an o-ring.

Doru mentioned something similar in this thread:
- E39 (1997 - 2003) > Broken DISA Valve

Originally Posted by doru

The seal is flush with the lips of the groove, having only a very small rib that will seat inside the receiving end - intake manifold, and that will produce the seal.

I'm not sure what this 'lip' actually is & why it disappears on the old DISA.

Q1: Does this additional lip flatten right away when a new DISA is installed; or does it take time to flatten out to nothing?

Originally Posted by Bazza-Aus

the original seal is moulded and "glued" into place.

Doru said the same thing over here:
- E39 (1997 - 2003) > Broken DISA Valve

Originally Posted by doru

Once the DISA is out, and in case it's still good (fat chance), the glued O-ring seal is certainly toast.

Q2: What glue should we use when installing a new DISA?

Shameless bump ...

QUESTION: What "glue" do you use when replacing your old DISA with a new DISA?